Central Venous Position Research Articles

Transcatheter treatment of tricuspid regurgitation by caval valve implantation—experimental evaluation of decellularized tissue valves in central venous position

Caval valve implantation has been suggested for transcatheter treatment of severe tricuspid regurgitation (TR). Combining the interventional technique with the promising surgical experience with decellularized valves, we sought to evaluate the functional and structural outcome of decellularized pericardial tissue valves (dTVs) in the low-pressure venous circulation in a chronic model of TR. Sixteen pericardial tissue valves were heterotopically implanted in the inferior and superior vena cava in a sheep model (54-98 kg; median 74.5 kg, n = 8) of severe TR. The devices were assembled using self-expanding nitinol stents and bovine pericardia decellularized by a detergent-based protocol (group dTV; n = 8). Glutaraldehyde-fixed pericardial tissue valves served as control (GaTV, n = 8). After 6 months, device function and structural maturation were analyzed using echocardiographic, histologic, immunohistologic, and electron microscopic approaches. After implantation, cardiac output increased significantly from 3.7 ± 1.1 l/min to 4.8 ± 1.1 l/min (P < 0.05) and competent valve function was verified by angiography. At 6 months, angiographic and echocardiographic evaluation revealed moderate to severe regurgitation in all GaTV. In contrast, five of the eight dTVs functioned well with only minor regurgitation. In these animals, autopsy revealed preserved valve structure with tender leaflets without signs of thrombosis or calcification. Conversely, GaTV showed severe degeneration with large calcification areas. Microscopic and histologic analysis confirmed endothelial repopulation in both valve types. However, additional interstitial reseeding was observed in decellularized valves. In the venous circulation in severe TR, decellularized valves show superior functional performance compared to Ga-fixed tissue valves. Macroscopic and microscopic analyses suggest preserved structural integrity and advanced endothelial and interstitial repopulation with evidence of less degradation in dTV. © 2014 Wiley Periodicals, Inc.

TCT-769 Functional Performance and Structural Maturation of Decellularised Pericardial Valves in Central Venous Position: An Experimental Study

R E S U L T S V I R E S U L T S V Functional Performance and Structural Maturation of Decellularized Pericardial Valves in Central Venous Position: An Experimental Study Alexander Lauten1, Adrian Laube1, Christoph Willich1, Harald Schubert2, Sabine Bischoff2, Sandor Nietzsche3, Markus Ferrari1, Arthur Lichtenberg4, Hans-R. Figulla1, Payam Akhyari4 1University Heart Center Jena, Department of Cardiology, Jena, Germany; 2Institute of Laboratory Animal Science, Jena, Germany; 3 DElectron Microscopy Center, Friedrich-SchillerUniversity Jena, 4Department of Cardiovascular Surgery and Institute for Experimental Surgery, Duesseldorf University Hospital, Duesseldorf P U R P O S E R E S U L T S I

Percutaneous central venous catheterization through the external jugular vein in children: is inserting the guide wire into the superior vena cava essential for successful catheterization?

Background/purposeThe external jugular vein (EJV) is an attractive alternative for percutaneous central venous catheterization (PCVC), with fewer complications. The inability to pass the guide wire into the superior vena cava (SVC) is, however, a major reason for the failure of this approach. The authors report a modification of the Seldinger technique to increase the effectiveness of this procedure in children. MethodsBetween May 2008 and June 2009, we performed 100 PCVCs consecutively in children using the Seldinger technique through the EJV (Step 1). In cases in which the guide wire could not be passed into the SVC, the guide wire was kept in the EJV; and only the catheter was introduced into the central venous position (Step 2). Differences between the standard and modified Seldinger techniques were analyzed. ResultsThe procedure with the standard Seldinger technique (Step 1) was successful in 13 (13%) out of 100 patients. In 84 (96.5%) of the 87 remaining patients, PCVC was achieved with the modified Seldinger technique, without the insertion of the guide wire until the SVC (Step 2). Altogether, 97 catheters (97%) were successfully inserted, with 85 (87.6%) correctly positioned in the SVC. In addition, there were 7 (7%) clinically irrelevant hematomas during catheterization. ConclusionsThe EJV is an excellent alternative anatomical location for the completion of PCVC in children. Placing the guide wire in a central position is not essential to the success rate of this approach. The proposed modified Seldinger technique allowed PCVC to be performed through the EJV safely and with a high success rate in children and adolescents.

Percutaneous caval stent valve implantation: investigation of an interventional approach for treatment of tricuspid regurgitation

Severe tricuspid regurgitation (TR) reduces cardiac output (CO) and increases central venous pressure leading to secondary organ dysfunction. To date, the open surgical approach is the only option to treat TR. Herein, we report our experience of treatment by percutaneous implantation of valved stents in the inferior vena cava (IVC) and superior vena cava (SVC) to substitute tricuspid valve function in a model of acute insufficiency. Acute TR grades III-IV was created in 13 sheep (54-75 kg) via papillary muscle and chordae avulsion using a 0.07 inch wire blade. Successful creation of TR was confirmed using angiography and by a prominent ventricular wave in central venous pressure recording. Two self-expanding nitinol stents containing a porcine pulmonary valve were then implanted in the IVC and SVC in a transcatheter approach. Implantation was performed through the right jugular vein by means of a 21 F catheter and guided by fluoroscopy. Haemodynamics were continuously monitored and valve function was verified by angiography and epicardial echocardiography. After successful implantation and proof of concept in the acute study (acute group, n = 9), chronic studies were (n = 4, 4 weeks follow-up) performed. Tricuspid regurgitation grades III-IV was successfully created in all animals and resulted in a significant reduction of CO. A ventricular wave in the IVC of 16.2 +/- 2.33 mmHg (acute group) and 14.9 +/- 1.71 mmHg (chronic group) confirmed the presence of severe TR. After deployment of the IVC and the SVC valve, the ventricular wave in the IVC significantly decreased to 13.9 +/- 2.97 mmHg (acute group) and 12.7 +/- 1.15 (chronic group), whereas CO significantly increased to 4.20 +/- 0.84 L/min (acute group) and 5.4 +/- 0.67 L/min (chronic group). At autopsy, correct device position was verified in all successfully implanted animals, no macroscopic damage resulting from the implantation procedure was observed. In high-grade tricuspid insufficiency, percutaneous implantation of valved stents in the central venous position reduces venous regurgitation and improves haemodynamics in the animal experiment. Implantation of one or two valves in central venous position is technically feasible. Functional replacement of the insufficient tricuspid valve leads to an increase in CO. This technique expands the potential therapeutic options for patients with relevant tricuspid valve regurgitation having a high risk for open heart surgery.

Semiquantitation of regional myocardial blood flow in normal human subjects by first-pass magnetic resonance imaging

The purpose of this study was to investigate the feasibility of first-pass MR imaging for measurement of regional myocardial blood flow in human beings. The first pass of the contrast agent Gd-DTPA through the myocardium was imaged in 12 normal volunteers with an EGG-gated Turbo-Flash sequence. The MTT of the contrast agent through the myocardium after a bolus injection was derived from curves of SI versus time. The bolus was injected through an intravenous catheter, which was advanced to the central venous position (preferably the right atrium). To investigate myocardial input function, different bolus concentrations and catheter positions were compared. It is concluded that first-pass MR imaging is feasible in human subjects when a central injection of 0.03 mmol/kg of Gd-DTPA is applied. MTT values were similar throughout the myocardium of normal subjects at rest, reflecting normal perfusion. Absolute values of MTT were related to the myocardial input.

Venous Hyperoxia after Cardiac Arrest: Characterization of a Defect in Systemic Oxygen Utilization

Supranormal mixed venous oxygen saturation (mixed venous hyperoxia), although reported, has never been characterized in humans resuscitated from cardiac arrest (postarrest cardiogenic shock). By contrast, cardiogenic shock without cardiopulmonary arrest (primary cardiogenic shock) is accompanied by mixed venous hypoxia under similar conditions of low oxygen delivery (DO2). The appearance of mixed venous hyperoxia indicates an excessive supply relative to demand in perfused tissue or cellular impairment of oxygen utilization, ie, low systemic oxygen consumption (VO2). Failure to improve VO2 has been associated with a poor outcome in other shock states. This study evaluates the clinical significance of mixed venous hyperoxia and its implications for impaired systemic oxygen utilization. The oxygen transport patterns in surviving and nonsurviving cardiac arrest patients are compared for their prognostic and therapeutic implications. Consecutive, nonrandomized series. Large urban emergency department (ED). Adult normothermic, nontraumatic out-of-hospital cardiac arrest patients presenting to the ED who develop a return of spontaneous circulation (ROSC). On arrival to the ED, a fiberoptic catheter was placed in the central venous position for continuous central venous oxygen saturation monitoring (ScvO2). A proximal aortic catheter was placed via the femoral artery for blood pressure monitoring. Upon ROSC, the fiberoptic catheter was advanced to the pulmonary artery. Mean arterial pressure (MAP), cardiac index (CI), VO2, DO2, systemic oxygen extraction ratio (OER), and systemic vascular resistance index (SVRI-dynes.s/cm5.m2) were measured immediately and every 30 min. The duration of cardiac arrest (DCA) in minutes and amount of epinephrine (milligrams) administered during ACLS was recorded. Twenty-three patients were entered into the study. Survivors (living more than 24 h) and nonsurvivors (living less than 24 h) were compared. These findings indicate an impairment of systemic oxygen utilization in postarrest cardiogenic shock patients. In spite of a lower DO2 than survivors, the OER in nonsurvivors remained lower than expected. Venous hyperoxia is a clinical manifestation of this derangement. Epinephrine dose may have a causal relationship. The inability to attain a VO2 of greater than 90 ml/min.m2 after the first 6 h of aggressive therapy was associated with a 100 percent mortality in 24 h.

Effects of different gas flow patterns on central circulation during respirator treatment.

The effects of different inspiratory gas flow patterns on the central circulation during respirator treatment were investigated, first with a retrospective study consisting of 15 patients, where the effects on the mean intrathoracic pressure were represented by the variations in the amplitude and time development of the oesophageal pressure curve. In another study on eight intensive care patients undergoing respirator treatment, right-sided heart catheterisation was performed with pressure recordings in the central venous position, the right ventricle, the pulmonary artery and in the pulmonary capillary venous position. Estimations of the arterial-mixed venous oxygen content difference were also made. The development and transmission of the airway pressure curve to the central circulation were illustrated and discussed. The results showed very small effects on the mean intrathoracic pressure from different inspiratory gas flow patterns, and, therefore, it could be expected that the effects on the central circulation would be insignificant. This was also the conclusion in the catheterisation study. No important changes in the pressures of the a-vo2 difference occured. Most of the characteristics of a particular gas flow pattern are lost during the passage through the airways and are not transmitted to the oesophagus or the central vessels.

Central Venous Catheterization Via the External Jugular Vein

CENTRAL venous pressure (CVP) measurement provides valuable clinical data during the perioperative period. A variety of routes and techniques for obtaining CVP data have been described. Cannulation of the antecubital vein is easy, but passage of a long catheter to a central location from the antecubital site is frequently difficult and unsuccessful. Cannulation of the subclavian or internal jugular vein provides reliable and accurate CVP, but is technically demanding and has resulted in severe complications. Peripheral venous pressure measurement from the external jugular vein can accurately reflect CVP, but is position-dependent and often unreliable. Passage of a catheter into a central venous position via the external jugular vein is very difficult with present methods. This study was designed to evaluate an easy, dependable, and safe method of catheter placement in the superior vena cava via the external jugular vein, employing a flexible angiographic wire catheter guide (J-wire). Methods A pilot